Squat Muscle Activation Patterns with Hip Rotations in Subjects with Genu Varum Deformity

Abstract

The purpose of this study was to compare muscle activation during the squat with different hip rotations (neutral, 15, 30, and 45° of internal and external hip rotation) in subjects with and without Genu Varum deformity deformity. Surface electromyography were recorded from 32 men with (n=16) and without (n=16) Genu Varum deformity. In the Genu Varum deformity group, the squats with 30, 45 and 15° of internal rotations of the hip showed significantly greater gluteus medius activation as compared to other positions. Moreover, the tensor fascia lata activity increased with greater external rotation of the hip, and significantly more than hip internal rotations (p<0.05). For vastus medialis and vastus lateralis, both hip internal and external rotation showed a significantly greater activation compared to the neutral hip positions (p<0.05). There were significant differences in the gluteus medius:tensor fascia lata activity ratio (p=0.001) and the vastus medialis: vastus lateralis activity ratio (p=0.001) between the different hip positions in the Genu Varum deformity and healthy groups. These results demonstrate that muscle activation patterns varied significantly with the position of different hip rotation in both groups. Those with Genu Varum deformity may use this information to aid in an injury prevention strategy by choosing squat positioning that favorably alters muscle activation patterns.

Effect of external isometric hip rotation force on lower extremity muscles activities during pelvic drop with different hip positions

“…On the other hand, the synergist muscles work together and affect each other [13][14][15][16] , therefore it is important to examine them together in electromyography studies. Because it is shown that muscle imbalance or changes in muscle activity patterns between them are associated with non-contact injuries such as PFPS and ITBS 7 .…”

“…In a similar study of isometric hip external rotation during single-leg stance, Schmitz et al 20 detected an increase in Gmed activity in response to isometric hip external rotation force. On the other hand, changes in the positions of hip rotations have been shown to be associated with changes in Gmed activity and can cause altered lower extremity alignment or be itself affected by postural malalignment 13 , 21 .…”

The effects of the Posterior X Taping versus augmented feedback on lower‐extremity kinematic and muscle activity pattern during unilateral weight‐bearing activities in men with tibiofemoral varus malalignment

“…It is well established that biomechanical deficiencies including excessive adduction and internal rotation of the hip and tibiofemoral external rotation and, subsequently altered muscle activity patterns during functional activities can be associated with overuse injuries [3][4][5][6][7]. Thus, it is important to assess and correct the movement defects, otherwise, over time this can cause more malalignment, exacerbating the symptoms of osteoarthritis, increasing the risk of overuse injuries such as iliotibial band and patellofemoral pain syndromes, and leading to other problems [8][9][10][11][12][13].…”

The Effect of Isometric Hip External Rotation on Lower Extremity Muscles Activities During Pelvic Drop With Different Positions of the Hip Rotation in Subjects With and Without Genu Valgum: Controlled Laboratory Study

“…On the other hand, the synergist muscles work together and affect each other [11][12][13][14], therefore it is important to examine them together in electromyography studies. Because it is shown that muscle imbalance or changes in muscle activity patterns between them are associated with non-contact injuries such as PFPS and ITBS [5].…”

“…In a similar study of isometric hip external rotation during single-leg stance, Schmitz et al [18] detected an increase in Gmed activity in response to isometric hip external rotation force. On the other hand, changes in the positions of hip rotations have been shown to be associated with changes in Gmed activity and can cause altered lower extremity alignment or be itself affected by postural malalignment [11,19].…”